CVE-2026-51766: n/a

This vulnerability arises from improper access control in the setDevReboot function of TOTOLINK T6 firmware 4.1.5cu.748_B20211015. An unauthenticated attacker can send a specially crafted MQTT message to the cs_broker component, triggering a reboot of the local device. If the device is a master in a mesh network, the reboot command can fan out to connected mesh slave devices, causing widespread disruption. The CVSS 3.1 base score is 7.5, reflecting network attack vector, low attack complexity, no privileges or user interaction required, and an impact limited to availability (device reboot). No patch or official remediation information is currently available.

The vulnerability allows an unauthenticated attacker to cause a denial of service by rebooting the affected device remotely. In mesh network configurations, this can extend to multiple devices, amplifying the disruption. There is no impact on confidentiality or integrity reported. This can affect network availability and potentially disrupt services relying on the affected devices.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider restricting network access to the MQTT broker component or isolating the device from untrusted networks to reduce exposure. Monitor vendor communications for updates on patches or official mitigations.